Abstract

Background

Diminishing supplies of fossil fuels and oil spills are rousing to explore the alternative
sources of energy that can be produced from non-food/feed-based substrates. Due to
its abundance, sugarcane bagasse (SB) could be a model substrate for the second-generation
biofuel cellulosic ethanol. However, the efficient bioconversion of SB remains a challenge
for the commercial production of cellulosic ethanol. We hypothesized that oxalic-acid-mediated
thermochemical pretreatment (OAFEX) would overcome the native recalcitrance of SB
by enhancing the cellulase amenability toward the embedded cellulosic microfibrils.

Conclusions

OAFEX treatment revealed marked hemicellulose degradation, improving the cellulases’
ability to access the cellulignin and release fermentable sugars from the pretreated
substrate. The ultrastructure of SB after OAFEX and enzymatic hydrolysis of cellulignin
established thorough insights at the molecular level.